Wasps happening? Decline in wasp population following 2012 downpours

The wasp may not be the most welcome summer visitor but its buzzing presence has been strangely absent in Ireland this year.

July was one of our hottest months on record but the insect has been missing from its usual haunts of picnics, barbecues, and ice cream cones.

Numbers are low this year because of a huge decline in the wasp population in the washout summer of 2012, according to experts.

Alan Stubbs, from the Buglife Conservation charity, said the insect is still trying to recover from last year’s inclement conditions.

He said: “Last year was so wet that wasps did very poorly. Low numbers this year are a carryover as few queens went into hibernation.

“Social wasps, or what I call jampot wasps, normally undergo cycles of good and poor years. We happen to be in an exceptional low year at the moment.”

The population of Irish wasps depends on queens who establish colonies and lay the eggs in underground nests. At the end of summer a nest can contain up to 5,000 wasps on average, and if it has been a particularly hot summer, this number can rise to around 10,000.

Blasts of hot and then cold weather in the spring can be detrimental to wasp colonies as queens come out of hibernation too early only to be hit by cold temperatures.

Mr Stubbs said the cold spring in Ireland and Britain would have added to the wasps’ woes. “The queen needs good weather to found a new colony in the spring. Only when the colony has built up strong numbers of workers can it afford to feed larger grubs which become males and new queens.

“After mating, only the new queens survive through to the next year. The remaining workers perish when winter sets in as there are hardly any insects to feed on and it is too cold to fly.”

The washout summer of 2012 is also responsible for diminishing the populations of many ground-nesting birds like the corncrake.

A lone corncrake in the Shannon Callows is said to be the last survivor of his species in the Midlands due to flooding nearly every summer of the last decade.